Splatterhouse (2010)- Lets you play the original trilogy once your beat the game.
Sam and Max Save the World and Beyond Time and Space- Includes the original versions with purchase
Broken Sword: Shadow of the Templars Director's Cut- Includes the original version of the game with purchase on Steam/GOG

Castlevania: The Dracula X Chronicles - Includes the original ''Rondo of Blood'' that gets unlocked after you pick up an item in stage 4 of the base game.

Celeste kinda

Odin Sphere: Leifthrasir includes the original game (Odin Sphere) as well; you can select it from the main menu.

Thank you all! I'll be adding them asap.

Day of the Tentacle Remastered

Battlezone 360

Danke schön.